Metro: 2033 - Weaponsmith 04/06/2016

I noticed a lot of people missed this achievement so I dug into my backup saves and I'm pretty sure this save was right before i got the achievement, but i can't remember exactly because its been a few months since i played this game. It's in Polis, just pick up the Kalash 2012 and get a kill with it, let me know if it works or not.